Low Loss Pre-Pregs and Laminates and Compositions Useful for the Preparation Thereof

ABSTRACT

In accordance with the present invention, compositions are described which are useful, for example, for the preparation of metal-clad laminate structures, methods for the preparation thereof, and various uses therefor. Invention metal-clad laminate structures are useful, for example, in the multi-layer board (MLB) industry, in the preparation of burn-in test boards and high reliability boards, in applications where low coefficient of thermal expansion (CTE) is beneficial, in the preparation of boards used in down-hole drilling, and the like.

RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 12/483,166filed Jun. 11, 2009.

FIELD OF THE INVENTION

The present invention relates to low loss pre-preg materials andlaminates prepared therefrom, as well as compositions useful for thepreparation thereof.

SUMMARY OF THE INVENTION

In accordance with the present invention, there are provided novelcompositions which are useful, for example, for the preparation ofmetal-clad laminate structures, methods for the preparation thereof, andvarious uses therefor. Invention metal-clad laminate structures areuseful, for example, in the multi-layer board (MLB) industry, in thepreparation of burn-in test boards and high reliability boards,applications where low coefficient of thermal expansion (CTE) isbeneficial, in the preparation of boards used in down-hole drilling, andthe like.

For example, materials employed in the preparation of equipment used incellular telecommunications, laminate-based chip carriers, and the like,must meet a number of criteria, including electrical performancecriteria (e.g., low loss, low dielectric constant, and the like),physical performance criteria (e.g., good heat resistance, gooddimensional stability without substantial loss of other desirableperformance properties, good adhesion to substrate(s), toughness, andthe like), and will also be environmentally friendly (e.g.,substantially halogen-free, lead-free, low volatile organic carbon, andthe like).

In view of the high demand and widespread use of such materials, inaddition to meeting the above-described electrical and physicalperformance properties, it is further desirable that such materials canbe prepared from relatively inexpensive starting materials employingreadily scalable, low cost processes. The present invention addressesthese and other needs as described in greater detail herein.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with one aspect of the present invention, there areprovided compositions comprising:

-   -   (a) a first resin which, upon curing, forms a triazine        structure,    -   (b) an optional second resin which, when present, modifies the        electrical, mechanical and/or thermal properties of said        composition,    -   (c) a substantially halogen-free, phosphorus-containing flame        retardant having an atomic phosphorus content in the range of        about 1-20 weight percent, based on the total weight of the        resin components (i.e., (a)+(b)), and    -   (d) a quantity of particulate filler(s) consistent with the        desired electrical and/or physical properties of said        composition (e.g., dielectric constant and/or loss factor        thereof);

wherein said composition has a low dielectric constant and a lowdielectric loss factor.

As used herein, “substantially halogen-free” refers to materials havinga halogen content of no greater than about 1000 ppm halogen; withmaterials having a halogen content of no greater than about 500 ppmhalogen being preferred; and materials having a halogen content of nogreater than about 100 ppm being especially preferred.

Invention compositions can be employed in a number of applications,e.g., for the preparation of electrical laminates for the manufacture ofprinted circuit boards, and the like. Among the many benefits ofinvention compositions is the fact that such compositions, when appliedto a suitable metal substrate across different metal weights andthicknesses, have excellent adhesion properties, typically displayingpeel strengths of at least 3 pounds/inch, and preferably displaying peelstrengths of 5 or more pounds/inch across different metal weights andthicknesses (e.g., copper thicknesses as low as 0.5 ounce are suitable).

Exemplary first resin materials contemplated for use herein, i.e.,resins which, upon curing, form a triazine structure, are typicallyderived from cyanate esters. Exemplary cyanate ester resins contemplatedfor use in the practice of the present invention include resins preparedfrom compounds such as those described in U.S. Pat. Nos. 5,358,992,5,447,988, 5,489,641, 5,646,241, 5,718, 941 and 5,753,748, each of whichare hereby incorporated by reference herein in their entirety. Forinstance, cyanate esters useful as a component in the inventioncompositions include dicyanatobenzenes, tricyanatobenzenes,dicyanatonaphthalenes, tricyanatonaphthalenes, dicyanato-biphenyl,bis(cyanatophenyl)methanes and alkyl derivatives thereof,bis(dihalocyanatophenyl)propanes, bis(cyanatophenyl)ethers,bis(cyanatophenyl)sulfides, bis(cyanatophenyl)propanes,phosphorus-containing cyanate esters (e.g.,tris(cyanatophenyl)phosphites, tris(cyanatophenyl)phosphates, and thelike), bis(halocyanatophenyl)methanes, cyanated novolac,bis[cyanatophenyl(methylethylidene)]benzene, cyanatedbisphenol-terminated thermoplastic oligomers, and the like, as well ascombinations of any two or more thereof.

More specifically contemplated for use herein are aryl compounds havingat least one cyanate ester group on each molecule; such compounds maygenerally be represented by the formula Ar(OCN)_(m), where Ar is anaromatic radical and m is an integer from 2 to 5. The aromatic radicalAr should contain at least 6 carbon atoms, and may be derived, forexample, from aromatic hydrocarbons, such as phenyl, biphenyl,naphthalene, anthracene, or the like. The aromatic radical Ar may alsobe derived from a polynuclear aromatic hydrocarbon in which at least twoaromatic rings are attached to each other through a bridging group. Alsoincluded are aromatic radicals derived from novolac-type phenolicresins—i.e., cyanate esters of these phenolic resins. Ar may alsocontain further ring-attached, non-reactive substituents.

Examples of such cyanate esters include, for instance,1,3-dicyanatobenzene; 1,4-dicyanatobenzene; 1,3,5-tricyanatobenzene;1,3-, 1,4-, 1,6-, 1,8-, 2,6- or 2,7-dicyanatonaphthalene;1,3,6-tricyanatonaphthalene; 4,4′-dicyanato-biphenyl;bis(4-cyanatophenyl)methane and 3,3′,5,5′-tetramethylbis(4-cyanatophenyl)methane;2,2-bis(3,5-dichloro-4-cyanatophenyl)propane;2,2-bis(3,5-dibromo-4-dicyanatophenyl)propane;bis(4-cyanatophenyl)ether; bis(4-cyanatophenyl)sulfide;2,2-bis(4-cyanatophenyl)propane; tris(4-cyanatophenyl)-phosphite;tris(4-cyanatophenyl)phosphate; bis(3-chloro-4-cyanatophenyl)methane;cyanated novolac; 1,3-bis[4-cyanatophenyl-1-(methylethylidene)]benzene,cyanated bisphenol-terminated polycarbonate or other thermoplasticoligomer, and the like, as well as combinations of any two or morethereof.

Particularly desirable cyanate esters contemplated for use herein areavailable commercially under the tradename “AROCY”[1,1-di(4-cyanatophenylethane)]. The structures of three “AROCY” cyanateesters are shown below:

Presently preferred cyanate ester monomers from which the triazines areprepared include bisphenol-A cyanate esters, hexafluorobisphenol-Acyanate esters, bisphenol-E cyanate esters, tetramethylbisphenol-Fcyanate esters, bisphenol-M cyanate esters, phenol Novolac cyanateesters, bisphenol-C cyanate esters, dicyclopentadienyl-bisphenol cyanateesters, Novolac cyanate esters, and the like, as well as mixtures of anytwo or more thereof.

Optional second resins contemplated for use herein include resins which,when present in invention formulations, modify the low dielectric lossfactor and the dielectric constant of the resulting composition.Exemplary second resins include polyphenylene oxides, styrene-maleicanhydride co-polymers, carboxy-terminated butadiene nitrile resins,multifunctional epoxies, low-halogen epoxies, bis-maleimides, and thelike, as well as mixtures of any two or more thereof.

Exemplary polyphenylene oxides contemplated for use herein includecompounds of the structure:

-[Ph-O]_(n)—

wherein Ph is an optionally substituted phenyl ring, and n falls in therange of about 10 up to about 200; with n in the range of about 10-100presently preferred.

Exemplary styrene-maleic anhydride co-polymers contemplated for useherein include alternating co-polymers of the structure:

—[CH(Ph)-CH₂—SA]_(m)-

as well as block co-polymers of the same components, wherein Ph is anoptionally substituted phenyl ring, SA is an optionally substitutedsuccinic anhydride residue, and m falls in the range of about 5 up toabout 200; with m in the range of about 10-100 presently preferred.

Exemplary carboxy-terminated butadiene nitrile resins contemplated foruse herein include compounds having one or more of the followingrepeating units:

—CH₂—CH═CH—CH₂—CH(CN)—CH₂—

a sufficient number of carboxy groups (—C(O)OH) thereon to provide acarboxy functionality in the range of about 1-5, and an elastomercontent of no greater than about 20% by weight.

Exemplary multifunctional epoxies contemplated for use herein includecompounds containing multiple epoxide units, wherein curing of theindividual epoxide units of the multifunctional epoxies creates a threedimensional network, resulting in a high Tg product. An exemplarymultifunctional epoxy is a phenol novolac epoxy with pendent epoxideunits on the side chains thereof.

As employed herein, “hydrocarbyl” refers to saturated or unsaturatedradicals having 1 up to 20 carbon atoms, preferably 2-10 carbon atoms.Exemplary hydrocarbyl radicals include alkyl, alkylene, alkenyl,alkenylene, alkynyl, alkynylene, cycloalkyl, cycloalkylene,cycloalkenyl, cycloalkenylene, aryl, arylene, and the like. Similarly,“substituted hydrocarbyl” comprises saturated or unsaturated hydrocarbylgroups further bearing one or more substituents selected from hydroxy,alkoxy (of a lower alkyl group), mercapto (of a lower alkyl group),cycloalkyl, substituted cycloalkyl, heterocyclic, substitutedheterocyclic, aryl, substituted aryl, heteroaryl, substitutedheteroaryl, aryloxy, substituted aryloxy, halogen, trifluoromethyl,cyano, nitro, nitrone, amino, amido, C(O)H, acyl, oxyacyl, carboxyl,carbamate, sulfonyl, sulfonamide, sulfuryl, and the like.

Exemplary low-halogen epoxies contemplated for use herein includeepoxies having a residual halogen content of no greater than 1000 ppm.

Exemplary bis-maleimides contemplated for use herein include maleimideshaving the structure:

wherein:

X is optionally substituted alkylene, cycloalkylene, arylene,polyarylene, heteroarylene or polyheteroarylene,

each R is independently H or optionally substituted lower alkyl, and

m is at least 2 (up to about 10).

As employed herein, “alkyl” refers to hydrocarbyl radicals having 1 upto 20 carbon atoms, preferably 2-10 carbon atoms; and “substitutedalkyl” comprises alkyl groups further bearing one or more substituentsselected from hydroxy, alkoxy (of a lower alkyl group), mercapto (of alower alkyl group), cycloalkyl, substituted cycloalkyl, heterocyclic,substituted heterocyclic, aryl, substituted aryl, heteroaryl,substituted heteroaryl, aryloxy, substituted aryloxy, halogen,trifluoromethyl, cyano, nitro, nitrone, amino, amido, C(O)H, acyl,oxyacyl, carboxyl, carbamate, sulfonyl, sulfonamide, sulfuryl, and thelike.

As employed herein, “lower alkyl” refers to hydrocarbyl radicals having1 up to 6 carbon atoms, preferably 1-4 carbon atoms; and “substitutedlower alkyl” comprises lower alkyl groups further bearing one or moresubstituents as described herein.

As employed herein, “alkylene” refers to divalent hydrocarbyl radicalshaving 1 up to 20 carbon atoms, preferably 2-10 carbon atoms; and“substituted alkylene” comprises alkylene groups further bearing one ormore substituents as set forth above.

As employed herein, “cycloalkylene” refers to divalent cyclicring-containing groups containing in the range of about 3 up to 8 carbonatoms, and “substituted cycloalkylene” refers to cycloalkylene groupsfurther bearing one or more substituents as set forth above.

As employed herein, “arylene” refers to divalent aromatic groups havingin the range of 6 up to 14 carbon atoms and “substituted arylene” refersto arylene groups further bearing one or more substituents as set forthabove.

As employed herein, “polyarylene” refers to a divalent moiety comprisinga plurality (i.e., at least two, up to about 10) divalent aromaticgroups (each having in the range of 6 up to 14 carbon atoms), whereinsaid divalent aromatic groups are linked to one another directly, or viaa 1-3 atom linker; and “substituted polyarylene” refers to polyarylenegroups further bearing one or more substituents as set forth above.

As employed herein, “heteroarylene” refers to divalent aromatic groupscontaining one or more heteroatoms (e.g., N, O, S, or the like) as partof the ring structure, and having in the range of 3 up to 14 carbonatoms; and “substituted arylene” refers to arylene groups furtherbearing one or more substituents as set forth above.

As employed herein, “polyheteroarylene” refers to a divalent moietycomprising a plurality (i.e., at least two, up to about 10)heteroarylene groups (each containing at least one heteroatom, and inthe range of 3 up to 14 carbon atoms), wherein said heteroarylene groupsare linked to one another directly, or via a 1-3 atom linker; and“substituted polyheteroarylene” refers to polyheteroarylene groupsfurther bearing one or more substituents as set forth above.

In some embodiments of the present invention, X of the above-describedcrosslinkable maleimide is optionally substituted alkylene.

In other embodiments of the present invention, X of the above-describedcrosslinkable maleimide is optionally substituted cycloalkylene.

In still other embodiments of the present invention, X of theabove-described crosslinkable maleimide is optionally substitutedarylene.

In yet other embodiments of the present invention, X of theabove-described crosslinkable maleimide is optionally substitutedbis-arylene. Exemplary bis-arylene compounds contemplated for use in thepractice of the present invention have the structure:

—Ar—Y—Ar—,

wherein:

each Ar is independently phenylene or substituted phenylene, and

Y is a bond, —O—, —S(O)_(n)—, wherein m is 0, 1 or 2, or —(CR′₂)_(x)—,wherein each R′ is independently H, halogen, or optionally substitutedlower alkyl, and x is 1-10.

In presently preferred embodiments of the present invention, each Ar ofthe above-described bis-arylene moiety is optionally substitutedphenylene, Y is —(CR′₂)_(x)—, each R′ is independently H or lower alkyl,and x is 0 or 1. In particularly preferred embodiments, X is-Ph-CH₂-Ph-, and each phenylene is optionally substituted. Optionalsubstitution of the phenylene moieties is preferably at the meta or paraposition.

Exemplary crosslinkable maleimides contemplated for use in the practiceof the present invention are selected from the group consisting ofN,N′-m-phenylene bismaleimide, N,N′-p-phenylene bismaleimide,N,N′-m-toluilene bismaleimide, N,N′-4,4′-biphenylene bismaleimide,N,N′-4,4′-[3,3′-dimethyl-biphenylene]bismaleimide,N,N′-4,4′-[3,3′-dimethyldiphenylmethane]bismaleimide,N,N′-4,4′-[3,3′-diethyldiphenylmethane]bismaleimide,N,N′-4,4′-diphenylmethane bismaleimide, N,N′-4,4′-diphenylpropanebismaleimide, N,N′-4,4′-diphenylether bismaleimide,N,N′-3,3′-diphenylsulfone bismaleimide, N,N′-4,4′-diphenylsulfonebismaleimide, 2,2-bis[4-(4-maleimidephenoxy)phenyl]nonane,2,2-bis[3-tertiary butyl-4-(-maleimidephenoxy)phenyl]propane,2,2-bis[3-secondary butyl-4-(4-maleimidephenoxy)phenyl]propane,1,1-bis[4-(4-maleimidephenoxy)phenyl]decane,1,1-bis[2-methyl-4-(4-maleimidephenoxy)-5-tertiary butylphenyl]-2-methylpropane,4,4′-cyclohexylidene-bis[1-(4-maleimidephenoxy)-2-(1,1-dimethylethyl)benzene],4,4′-methylene-bis[1-(4-maleimidephenoxy)-2,6-bis(1,1′-dimethylethyl)benzene],4,4′-methylene-bis[1-(4-maleimidephenoxy)-2,6-di-secondary butylbenzene],4,4′-cyclohexylidene-bis[1-(4-maleimidephenoxy)-2-cyclohexylbenzene],4,4′-methylene-bis[1-(maleimidephenoxy)-2-nonylbenzene],4,4′-(1-methylethylidene)-bis[1-(maleimidephenoxy)-2,6-bis(1,1′-dimethylethyl)benzene,4,4′-(2-ethylhexylidene)-bis[1-(maleimidephenoxy)-benzene],4,4′-(1-methylheptylidene)-bis[1-(maleimidephenoxy)-benzene],4,4′-cyclohexylidene-bis[1-(maleimidephenoxy)-3-methylbenzene], and thelike.

The relative weight ratios of the above-described components can varywidely. Typically, the weight ratio between (a) and (b), when (b) ispresent, is at least about 1:1 up to about 20:1. The composition ofclaim 1 wherein the weight ratio between (a) and (b), when (b) ispresent, falls in the range of about 2:1 up to about 10:1.

As employed herein, “about” means in quantitative terms plus or minus10%.

Exemplary substantially halogen-free, phosphorus-containing compoundscontemplated for use herein can be either reactive or non-reactive, andinclude organo-phosphates, phosphonates, phosphorus-based phenolichardeners, phosphorus-containing cyanate esters, phosphorus-containingtriazines, and the like, as well as mixtures of any two or more thereof.

Exemplary organo-phosphates contemplated for use herein include diphenylphosphate, triphenyl phosphate, and the like, as well as mixtures of anytwo or more thereof.

Exemplary phosphonates contemplated for use herein include compoundssuch as m-phenylene methyl phosphonate.

Exemplary phosphorus-based phenolic hardeners contemplated for useherein include DOW XZ92741, and the like, as well as mixtures of any twoor more thereof.

As readily understood by those of skill in the art, the atomicphosphorus content contemplated for use in the practice of the presentinvention can vary widely. Typically, the atomic phosphorus content willfall in the range of about 1-20 wt %, based on the total weight ofcomponents (a) and (b), taken together; preferably, the phosphoruscontent falls in the range of about 1-10 wt %, based on the total weightof components (a) and (b), taken together; and a phosphorus content inthe range of about 3-5 wt % being presently preferred.

Alternatively, the amount of atomic phosphorus employed in the practiceof the present invention can be expressed as the ratio of component(a):(c), wherein the ratio of (a):(c) will typically fall in the rangeof at least about 1:20 up to about 20:1. In some embodiments of thepresent invention, the weight ratio between (a) and (c) falls in therange of at least about 1:10 up to about 10:1. In other embodiments ofthe present invention, the weight ratio between (a) and (c) falls in therange of at least about 1:5 up to about 5:1. In still other embodimentsof the present invention, the weight ratio between (a) and (c) falls inthe range of about 1:1 up to about 3:1.

In certain embodiments of the present invention, the substantiallyhalogen-free, phosphorus-containing flame retardant is supplemented bythe presence of one or more nitrogen-containing synergist(s). Exemplarynitrogen-containing synergists contemplated for use herein include isocyanurates, urea derivatives, melamine derivatives, phosphazenederivatives, nitrogen-containing phenolic resins, nitrogen-containingepoxy resins, and the like, as well as mixtures of any two or morethereof.

Additional flame retardants contemplated for optional use in thepractice of the present invention include substantially halogen-freefire retardants, halogenated fire retardants, additive and/or reactiveflame retardants which may serve as intumescents or char formers,silanes, siloxanes, low melting glasses, zinc-, boron-, aluminum-, ormagnesium-based fire retardants, and the like.

Specific compounds contemplated for use as fire retardants includenitrogenes (e.g., melamine derivatives), bromine-containing fireretardants (e.g., brominated styrenes), zinc- and/or boron-based fireretardants (e.g., zinc borate, zinc star hate, borax, and the like),aluminum-based fire retardants (e.g., aluminum trihydrate (ATH)),magnesium-based fire retardants (e.g., magnesium hydroxide), and thelike, as well as combinations of any two or more thereof.

Fillers contemplated for use in the practice of the present inventionmay be any of a variety of morphologies, e.g., angular, platelet,spherical, amorphous, sintered, fired, powder, flake, crystalline,ground, crushed, milled, and the like, or mixtures of any two or morethereof. Presently preferred particulate fillers contemplated for useherein are substantially spherical.

Such fillers may optionally be thermally conductive. Both powder andflake forms of filler may be used in the compositions of the presentinvention. Fillers having a wide range of particle sizes can be employedin the practice of the present invention. Typically particle sizesranging from about 500 nm up to about 300 microns are employed, withparticle sizes of less than about 100 microns being preferred, andparticle sizes in the range of about 5 up to about 75 microns beingparticularly preferred.

Filler is typically present in the range of about 50 parts by weight upto about 400 parts by weight, relative to the total weight of the resincomponents of the composition. Preferably, the quantity of filleremployed falls in the range of about 100 parts by weight up to about 350parts by weight, relative to the total weight of the resin components ofthe composition, with quantities in the range of about 200 parts byweight, up to about 300 parts by weight being especially preferred. Incertain embodiments of the invention, 275 parts filler by weight areespecially preferred.

A wide variety of fillers can be employed in the practice of the presentinvention, e.g., soft fillers (e.g., uncalcined talc), naturallyoccurring minerals (e.g., aluminum nitride, boron nitride, siliconcarbide, diamond, graphite, beryllium oxide, magnesia, silica, alumina,aluminum silicates, and the like), calcined naturally occurring minerals(e.g., enstatite), synthetic fused minerals (e.g., cordierite), treatedfillers (e.g., silane-treated minerals), organic polymers (e.g.,polytetrafluoroethylene), hollow spheres, microspheres, powderedpolymeric materials, and the like.

Exemplary fillers include talc, mica, calcium carbonate, calciumsulfate, aluminum nitride, boron nitride, silicon carbide, diamond,graphite, beryllium oxide, magnesia, silica, alumina, TiO₂, aluminumsilicate, aluminum-zirconium-silicate, cordierite, silane-treatedmineral, polytetrafluoroethylene, polyphenylene sulfide, and the like.

Thermally conductive fillers contemplated for optional use in thepractice of the present invention include, for example, aluminumnitride, boron nitride, silicon carbide, diamond, graphite, berylliumoxide, magnesia, silica, alumina, zirconium silicate, and the like.Preferably, the particle size of these fillers will be about 20 microns.If aluminum nitride is used as a filler, it is preferred that it bepassivated via an adherent, conformal coating (e.g., silica, or thelike).

Thermally conductive fillers are optionally (and preferably) renderedsubstantially free of catalytically active metal ions by treatment withchelating agents, reducing agents, nonionic lubricating agents, ormixtures of such agents. Such treatment is described in U.S. Pat. No.5,447,988, which is incorporated by reference herein in its entirety.

Optionally, a filler may be used that is not a thermal conductor. Suchfillers may be desirable to impart some other property to the adhesiveformulation such as, for example, reduced thermal expansion of the curedadhesive, reduced dielectric constant, improved toughness, increasedhydrophobicity, and the like. Examples of such fillers includeperfluorinated hydrocarbon polymers (i.e., TEFLON™), thermoplasticpolymers, thermoplastic elastomers, mica, fumed silica, fused silica,glass powder, and the like.

Invention compositions optionally include one or more additionalcomponents such as flexibilizers, anti-oxidants, dyes, pigments,surfactants, defoamers, silane coupling agents, dispersing agents,thixotropic agents, processing aids, flow modifiers, cure accelerators,strength enhancers, toughening agents, UV protectors (especially UVblocking dyes appropriate to enable Automatic-Optical Inspection (AOI)of Circuitry), and the like, as well as mixtures of any two or morethereof.

Flexibilizers (also called plasticizers) contemplated for use in certainembodiments of the present invention include compounds that reduce thebrittleness of the formulation, such as, for example, branchedpolyalkanes or polysiloxanes that lower the glass transition temperature(Tg) of the formulation. Such plasticizers include, for example,polyethers, polyesters, polythiols, polysulfides, and the like.Plasticizers, when employed, are typically present in the range of about0.5 wt. % up to about 30 wt. % of the formulation.

Anti-oxidants contemplated for use in the practice of the presentinvention include hindered phenols (e.g., BHT (butylatedhydroxytoluene), BHA (butylated hydroxyanisole), TBHQ (tertiary-butylhydroquinone), 2,2′-methylenebis(6-tertiarybutyl-p-cresol), and thelike), hindered amines (e.g., diphenylamine,N,N′-bis(1,4-dimethylpentyl-p-phenylene diamine,N-(4-anilinophenyl)methacrylamide,4,4′-bis(□,□-dimethylbenzyl)diphenylamine, and the like), phosphites,and the like. When used, the quantity of anti-oxidant typically falls inthe range of about 100 up to 2000 ppm, relative to the weight of thebase formulation.

Dyes contemplated for use in certain embodiments of the presentinvention include nigrosine, Orasol blue GN, phthalocyanines,fluorescent dyes (e.g., Fluoral green gold dye, and the like), and thelike. When used, organic dyes in relatively low amounts (i.e., amountsless than about 0.2% by weight) provide contrast.

Pigments contemplated for use in certain embodiments of the presentinvention include any particulate material added solely for the purposeof imparting color to the formulation, e.g., carbon black, metal oxides(e.g., Fe₂O₃, titanium oxide), and the like. When present, pigments aretypically present in the range of about 0.5 wt. % up to about 5 wt. %,relative to the base formulation.

Flow modifiers may optionally be employed in the practice of the presentinvention to alter the melt rheology in order to facilitate achievingdesired fill and/or lamination properties. Use of such optionaladditives may thereby (1) enhance the internal cohesion of the article,and/or (2) produce a multi-layered board by bonding resinous prepregs tolayers comprising etched circuitry with enhanced inter-laminaradhesion/bonding. When employed in accordance with the presentinvention, such additives are likely to be used at minimum loadinglevels (e.g., in the range of about 1 up to about 10 weight percent,based on the total weight of the formulation) to gain the benefit suchadditives can impart (e.g., enhanced heat and pressure induced flow)without compromising other physical and electrical properties.

Flow modifiers contemplated for use herein may be non-reactive orreactive (i.e., capable of participating in oxidative cross-linking).Such materials will desirably exhibit electrical and physical propertieswhich are compatible with all of the components of the above-describedcompositions.

Exemplary flow modifiers contemplated for use in the practice of thepresent invention may be non-reactive or reactive, and includemonomeric, oligomeric, or polymeric (i.e., thermoplastic) saturated(aliphatic) hydrocarbons, unsaturated hydrocarbons, and the like.

Cure accelerators contemplated for use in certain embodiments of thepresent invention include compounds which enhance the rate of cure ofthe base polymer system, such as, for example, catalytically activematerials, and the like.

Strength enhancers contemplated for use in certain embodiments of thepresent invention include compounds which increase the performanceproperties of the polymeric material to which they are added, such as,for example, crosslinking agents, and the like.

Toughening agents contemplated for use in the practice of the presentinvention are materials which impart enhanced impact resistance tovarious articles. Exemplary toughening agents include synthetic rubbercontaining compounds such as Hypro, Hypox, and the like.

UV protectors contemplated for use in certain embodiments of the presentinvention include compounds which absorb incident ultraviolet (UV)radiation, thereby reducing the negative effects of such exposure on theresin or polymer system to which the protector has been added. ExemplaryUV protectors include bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate,silicon, powdered metallic compounds, hindered amines (known in the artas “HALS”), and the like.

Defoamers contemplated for use in certain embodiments of the presentinvention include materials which inhibit formation of foam or bubbleswhen a liquid solution is agitated or sheared during processing.Exemplary defoamers contemplated for use herein include n-butyl alcohol,silicon-containing anti-foam agents, and the like.

Exemplary silane coupling agents contemplated for use in the practice ofthe present invention include materials which form a bridge betweeninorganic surfaces and reactive polymeric components, includingmaterials such as epoxy silanes, amino silanes, and the like.

Exemplary dispersing agents contemplated for use in the practice of thepresent invention include materials which prevent agglomeration ofparticulate fillers (which would result in the formation of overly largelocalized clumps of filler), including surfactants.

Exemplary thixotropic agents contemplated for use in the practice of thepresent invention include materials which cause liquids to have theproperty of enhanced flow when shear is applied, including materialssuch as high surface area fillers (e.g., fumed silica) having particlesizes in the range about 2-3 microns, or even submicron size.

Exemplary processing aids contemplated for use in the practice of thepresent invention include materials which modify the ability of aformulation to be shaped, formed or otherwise manipulated, withoutsubstantially impacting the intrinsic properties of the formulation.

In accordance with yet another embodiment of the present invention,there are provided articles comprising a partially or fully cured layerof the above-described composition on a suitable substrate.

As readily recognized by those of skill in the art, a variety ofsubstrates are suitable for use in the practice of the presentinvention, for example, polyesters, liquid crystalline polymers,polyamides (e.g., Aramids), polyimides, polyamide-imides, polyolefins,polyphenylene oxides, polyphenylene sulfides, polybenzoxazolines,conductive materials (e.g., conductive metals), and the like, as well ascombinations of any two or more thereof.

When conductive metal substrates are employed, such materials as silver,nickel, gold, cobalt, copper, aluminum, alloys of such metals, and thelike, are contemplated for use herein.

In accordance with still another embodiment of the present invention,there are provided methods of making the above-described articles (i.e.,articles comprising composition according to the invention on asubstrate), said methods comprising applying invention composition to asubstrate and, if diluent is optionally employed to facilitate suchapplication, removing substantially all diluent therefrom.

Optional diluents contemplated for use in the practice of the presentinvention include aromatic, aliphatic, cycloaliphatic, and the like, aswell as combinations of any two or more thereof. As readily recognizedby those of skill in the art, diluents may be reactive or non-reactive.Non-reactive diluents remain unchanged by the chemical processes thatmay occur in their presence, whereas reactive diluents participate inone way or another in the reaction, e.g., by dissolving one or more ofthe other reactants, by promoting reaction, or by being consumed as partof the reaction occurring in its presence.

Presently preferred diluents contemplated for optional use in thepractice of the present invention are non-reactive diluents which arerelatively non-polar. Exemplary diluents contemplated for use hereininclude methyl ethyl ketone (MEK), propylene glycol methyl ether (PM),propylene glycol methyl ether acetate (PMA), and the like, as well asmixtures of any two or more thereof.

In accordance with yet another embodiment of the present invention,there are provided prepregs produced by impregnating a porous substratewith a composition according to the invention, and, if diluent isoptionally employed to facilitate such application, subjecting theresulting impregnated substrate to conditions suitable to removesubstantially all of the diluent therefrom.

As readily recognized by those of skill in the art, a variety of poroussubstrates can be employed for the preparation of invention prepregs.For example, the substrate can be either woven or non-woven.

Exemplary materials employed for preparation of substrates contemplatedfor use herein include fiberglass, quartz, polyester fiber, polyamidefiber, polyimide fiber, polyamide-imide fiber, polyphenylene sulfidefiber, polyalkylene fiber, liquid crystalline polymer,poly(p-phenylene-2,6-benzobisoxazole), aramid fiber,polytetrafluoroethylene, a copolymer of tetrafluoroethylene andperfluoromethylvinyl ether (MFA), and the like, as well as mixtures ofany two or more thereof.

Presently preferred materials employed for preparation of substratescontemplated for use herein include woven glass, non-woven glass, wovenaramid fiber, non-woven aramid fiber, and the like.

In accordance with yet another embodiment of the present invention,there are provided methods of making prepregs comprising a poroussubstrate impregnated with a composition according to the invention,said methods comprising impregnating a porous substrate with inventioncomposition, and, if diluent is optionally employed to facilitate suchapplication, subjecting the resulting impregnated substrate toconditions suitable to remove substantially all of the diluenttherefrom. The resulting resin content will typically fall in the rangeof about 25 up to about 90%.

As employed herein, the term “porous substrate” refers to a woven ornon-woven substrate which can include, but is not limited to, wovenglass, non-woven glass, woven aramid fibers, non-woven aramid fibers,woven liquid crystal polymer fibers, non-woven liquid crystal polymerfibers, woven synthetic polymer fibers, non-woven synthetic polymerfibers, randomly dispersed fiber reinforcements, expandedpolytetrafluoroethylene (PTFE) structures and combinations of any two ormore thereof. Specifically, materials contemplated for use as the“porous substrate” can include, but are not limited to, fiberglass,quartz, polyester fiber, polyamide fiber, polyphenylene sulfide fiber,polyetherimide fiber, cyclic olefin copolymer fiber, polyalkylene fiber,liquid crystalline polymer, poly(p-phenylene-2,6-benzobisoxazole),copolymers of polytetrafluoroethylene and perfluoromethylvinyl ether(MFA) and combinations of any two or more thereof.

As employed herein, “combination,” when used to refer to polymers,embraces blends, copolymers, coplanar layers, and the like, of any twoor more of the polymer or resin materials.

In accordance with still another embodiment of the present invention,there are provided laminated sheets produced by layering and molding aprescribed number of sheets of the above-described prepreg.

Laminated sheets according to the invention have many particularlybeneficial properties, such as, for example, low dielectric constant,low electrical loss tangent, high thermal decomposition temperature, andthe like.

In a preferred embodiment, laminated sheets according to the presentinvention have a dielectric constant ≦4.5 nominal, electrical losstangent ≦0.02, and a glass transition temperature of at least 80° C.

In one aspect of the present invention, laminated sheets as describedherein may optionally further comprise one or more conductive layers.Such optional conductive layers are selected from the group consistingof metal foils, metal plates, electrically conductive polymeric layers,and the like.

In accordance with yet another embodiment of the present invention,there are provided methods of making a laminated sheet, said methodcomprising layering and molding a prescribed number of sheets of aprepreg according to the invention.

In accordance with a further embodiment of the present invention, thereare provided printed wiring boards produced by forming conductivepatterns on the surface of the above-described laminated sheet(s).

In accordance with a still further embodiment of the present invention,there are provided multilayer printed wiring boards produced by layeringand molding a prescribed number of sheets of the above-describedpatterned laminate layers, bonded together with one or more layers ofprepreg from which the printed wiring board layer was prepared.

In accordance with a still further embodiment of the present invention,there are provided methods of making printed wiring boards, said methodscomprising forming conductive patterns on the surface of a laminatedsheet according to the invention.

In accordance with yet another embodiment of the present invention,there are provided multilayer printed wiring boards produced by layeringand molding a prescribed number of sheets of the above-describedprepreg, to obtain a printed wiring board for an inner layer, andlayering the prepreg on the printed wiring board for an inner layerwhich forms conductive patterns on the surface.

In accordance with still another embodiment of the present invention,there are provided methods of making multilayer printed wiring board,said methods comprising layering and molding a prescribed number ofsheets of prepreg according to the invention, to obtain a printed wiringboard for an inner layer, and layering the prepreg on the printed wiringboard for an inner layer which forms conductive patterns on the surface.

In accordance with yet another embodiment of the present invention,there are provided methods for improving adhesion of low-halogen,phosphorus-containing flame retardant filled triazine-based formulationsto a substrate, said method comprising adding to said formulation anamount of an additional resin effective to improve the adhesion thereofto said substrate upon cure.

In accordance with yet another embodiment of the present invention,there are provided methods of adhering low-halogen,phosphorus-containing flame retardant filled triazine-based formulationsto a substrate, said method comprising applying an invention compositionas described herein to a suitable substrate, and curing saidcomposition.

In accordance with yet another embodiment of the present invention,there are provided methods for improving low dielectric loss factor oflow-halogen, phosphorus-containing flame retardant filled triazine-basedformulations, said method comprising adding to said formulation anamount of an additional resin effective to improve the low dielectricloss factor thereof upon cure.

In accordance with yet another embodiment of the present invention,there are provided methods for improving adhesion of filled,low-halogen, phosphorus-containing flame retardant triazine-basedformulations to a substrate, said method comprising replacing at least aportion of said filler with an amount of a different particulate fillereffective to improve the adhesion thereof to said substrate upon cure.

In accordance with yet another embodiment of the present invention,there are provided methods for improving low dielectric loss factor oflow-halogen, phosphorus-containing flame retardant triazine-basedformulations, said method comprising adding to said formulation anamount of a particulate filler effective to improve the low dielectricloss factor thereof upon cure.

The invention will now be described in greater detail by reference tothe following non-limiting examples.

Example 1

Exemplary low-halogen, phosphorus-containing flame retardant filledtriazine-based formulations according to the invention were preparedemploying different levels of filler, as summarized in the followingtable. Thus, the following formulations were prepared employing standardtechniques:

Formulation Components* RLD II 35 BTC-250 + Fyrol PMP + 300 phr of FB-8SRLD II 37 BTC-250 + Fyrol PMP + 200 phr of FB-8S RLD II 38 BTC-250 +Fyrol PMP + 100 phr of FB-8S RLD II 39 BTC-250 + Fyrol PMP + 0 phr ofFB- 8S silica RLD II 36 BTC-250 + XZ 92740** + 300 phr of FB-8S silica*BTC-250: Toughened Cyanate Ester resin from Lonza Fyrol PMP:phosphorous containing halogen free flame retardant from Supresta. FB-8Ssilica: spherical silica with a nominal particle size of 8 micron fromDenka Corporation **XZ92740 (non-halogenated epoxy resin) was added tothe formulation at 50:50 basis with regards to BTC-250

The performance properties of each of the above-described formulationswere determined employing standard techniques such as test method2.5.5.5, as described in Book No. IPZ 10-650. Results are summarized inthe following table.

Formulation Dk/Df (@10 GHz) RLD II 35 3.69/.0045  RLD II 37 3.69/0.0079RLD II 38 3.46/0.0062 RLD II 39 3.23/0.0092 RLD II 36 3.69/0.0079

Review of the experimental results presented above indicates thatcompositions according to the present invention have excellentperformance properties.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs.

The inventions illustratively described herein may suitably be practicedin the absence of any element or elements, limitation or limitations,not specifically disclosed herein. Thus, for example, the terms“comprising,” “including,” “containing,” etc. shall be read expansivelyand without limitation. Additionally, the terms and expressions employedherein have been used as terms of description and not of limitation, andthere is no intention in the use of such terms and expressions ofexcluding any equivalents of the features shown and described orportions thereof, but it is recognized that various modifications arepossible within the scope of the invention claimed.

Thus, it should be understood that although the present invention hasbeen specifically disclosed by preferred embodiments and optionalfeatures, modification, improvement and variation of the inventionsembodied therein herein disclosed may be resorted to by those skilled inthe art, and that such modifications, improvements and variations areconsidered to be within the scope of this invention. The materials,methods, and examples provided here are representative of preferredembodiments, are exemplary, and are not intended as limitations on thescope of the invention.

The invention has been described broadly and generically herein. Each ofthe narrower species and subgeneric groupings falling within the genericdisclosure also form part of the invention. In addition, where featuresor aspects of the invention are described in terms of Markush groups,those skilled in the art will recognize that the invention is alsothereby described in terms of any individual member or subgroup ofmembers of the Markush group.

All publications, patent applications, patents, and other referencesmentioned herein are expressly incorporated by reference in theirentirety, including all formulas and figures, to the same extent as ifeach were incorporated by reference individually. In case of conflict,the present specification, including definitions, will control.

Other embodiments are set forth within the following claims.

What is claimed:
 1. A laminate comprising: at least one low lossdielectric layer formed from a composition comprising: a first resinthat forms a triazine structure upon curing, a second resin comprisingat least one member selected from the group consisting of apolyphenylene oxide, a styrene-maleic anhydride copolymer, acarboxy-terminated butadiene nitrile resin, a multifunctional epoxyresin, a low-halogen epoxy resin and a bis-maleimide resin, asubstantially halogen-free, phosphorus-containing flame retardant havingan atomic phosphorus content in the range of about 1-20 weight percent,based on the total weight of the resin components, and a quantity of aparticulate filler.
 2. The laminate of claim 1 wherein the first resinis derived from a cyanate ester.
 3. The laminate of claim 1 wherein thefirst resin is derived from a Novolac cyanate ester.
 4. The laminate ofclaim 1 wherein said first resin is derived from a bisphenol-A cyanateester, a hexafluorobisphenol-A cyanate ester, a bisphenol-E cyanateester, a tetramethylbisphenol-F cyanate ester, a bisphenol-M cyanateester, a phenol Novolac cyanate ester, a bisphenol-C cyanate ester, adicyclopentadienyl-bisphenol cyanate ester, or a Novolac cyanate ester.5. The laminate of claim 1 wherein said substantially halogen-free,phosphorus-containing compound is an organo-phosphate, a phosphonate, aphosphorus-based phenolic hardener, a phosphorus-containing cyanateester, or a phosphorus-containing triazine.
 6. The laminate of claim 5wherein said organo-phosphate comprises at least one member selectedfrom the group consisting of diphenyl phosphate and triphenyl phosphate.7. The laminate of claim 1 wherein said flame retardant furthercomprises at least one nitrogen-containing synergist.
 8. The laminate ofclaim 7 wherein said at least one nitrogen-containing synergistcomprises at least one member selected from the group consisting of aniso cyanurate, a urea-containing compound, a melamine-containingcompound, a phosphazene-containing compound, a nitrogen-containingphenolic resin, and a nitrogen-containing epoxy resin.
 9. The laminateof claim 1 wherein said particulate filler is angular, platelet,spherical, amorphous, sintered, fired, powder, flake, crystalline,ground, crushed, milled, fumed or mixtures of any two or more thereof.10. The laminate of claim 1 wherein said particulate filler issubstantially spherical.
 11. The laminate of claim 1 wherein theparticle size of said particulate filler falls in the range of about 500nm up to about 300 micron.
 12. The laminate of claim 1 wherein saidfiller comprises at least one member selected from the group consistingof a naturally occurring mineral, a synthetic fused mineral, a treatedfiller, an organic polymer, a hollow sphere, a microsphere, or apowdered polymeric material.
 13. The laminate of claim 1 wherein saidfiller comprises at least one member selected from the group consistingof talc, mica, calcium carbonate, calcium sulfate, aluminum nitride,boron nitride, silicon carbide, diamond, graphite, beryllium oxide,magnesia, silica, alumina, Ti0₂, aluminum silicate, zirconium silicate,aluminum-zirconium-silicate, cordierite, silane treated mineral,polytetrafluoroethylene, and polyphenylene sulfide.
 14. The laminate ofclaim 1 wherein the quantity of filler employed falls in the range ofabout 50 parts by weight up to about 400 parts by weight, relative tothe total weight of the resin components of the composition.
 15. Thelaminate of claim 1 wherein the weight ratio between the first resin andthe second resin is in the range of about 1:1 to about 20:1.
 16. Thelaminate of claim 1 wherein the atomic phosphorus content is in therange of about 1-10 wt %, based on the total weight of the first resinand the second resin.
 17. The laminate of claim 1 wherein the low lossdielectric layer further comprises one or more agents selected from thegroup consisting of a flexibilizer, an anti-oxidant, a dye, a pigment, asurfactant, a defoamer, a silane coupling agent, a dispersing agent, athixotropic agent, a flow modifier, a cure accelerator, a strengthenhancer, a toughening agent, and a processing aid.
 18. The laminate ofclaim 1 wherein said low loss dielectric layer has a peel strength of atleast 3 pounds/inch.
 19. The laminate of claim 1 wherein the low lossdielectric layer has a dielectric constant ≦4.5 when measured at 10 GHz.20. The laminate of claim 1 wherein the low loss dielectric layer has adielectric loss factor ≦0.02 when measured at 10 GHz.
 21. The laminateof claim 19 wherein the composition has a dielectric loss factor ≦0.02when measured at 10 GHz.
 22. The laminate of claim 1 wherein the lowloss dielectric layer comprises an epoxy component comprising at leastone member selected from the group consisting of a multifunctionalepoxy, a nitrogen-containing epoxy, a low-halogen epoxy, anon-halogenated epoxy and an epoxy silane.
 23. The laminate of claim 1wherein the low loss dielectric layer comprises a multifunctional epoxycomponent.
 24. The laminate of claim 1 wherein the low loss dielectriclayer comprises a styrene-maleic anhydride copolymer.
 25. The laminateof claim 1 wherein the low loss dielectric layer comprises acarboxy-terminated butadiene nitrile resin.
 26. The laminate of claim 1further including a substrate, wherein the substrate is impregnated bythe composition.
 27. The laminate of claim 26 wherein the substrate iswoven.
 28. The laminate of claim 26 wherein the substrate is nonwoven.29. The laminate of claim 26 wherein the substrate comprises at leastone member selected from the group consisting of fiberglass, quartz, apolyester, a polyamide, a polyimide, a polyamide-imide, a liquidcrystalline polymer (LCP), a polyphenylene sulfide (PPS), apolyalkylene, a polyphenylene oxide (PPO), a polybenzoxazoline (PBO), anAramid, polytetrafluoroethylene, a copolymer of tetrafluoroethylene andperfluoromethylvinyl ether (MFA), and a conductive material.
 30. Thelaminate of claim 1 wherein the low loss dielectric layer is formed on asubstrate.
 31. The laminate of claim 30, wherein the substrate comprisesa polymer.
 32. The laminate of claim 30 wherein the substrate comprisesat least one member selected from the group consisting of a polyesterand a polyolefin.
 33. The laminate of claim 30 wherein the substratecomprises at least one member selected from the group consisting of apolyester, a polyamide, a polyimide, a polyamide-imide, a liquidcrystalline polymer (LCP), a polyphenylene sulfide (PPS), apolyphenylene oxide (PPO), a polybenzoxazoline (PBO), an Aramid, and aconductive material.
 34. The laminate of claim 30 wherein the substratecomprises a conductive material.
 35. The laminate of claim 30 whereinthe conductive material includes at least one member selected from thegroup consisting of silver, nickel, golf, cobalt, copper, aluminum, andalloys thereof.
 36. An article comprising the laminate of claim
 1. 37.An article comprising the laminate of claim
 26. 38. An articlecomprising the laminate of claim
 30. 39. A method of making a laminatecomprising: forming a low loss dielectric layer from a compositioncomprising: a first resin that forms a triazine structure upon curing, asecond resin comprising at least one member selected from the groupconsisting of a polyphenylene oxide, a styrene-maleic anhydridecopolymer, a carboxy-terminated butadiene nitrile resin, amultifunctional epoxy resin, a low-halogen epoxy resin and abis-maleimide resin, a substantially halogen-free, phosphorus-containingflame retardant having an atomic phosphorus content in the range ofabout 1-20 weight percent, based on the total weight of the resincomponents, and a quantity of a particulate filler, and curing the lowloss dielectric layer.
 40. The method of claim 39 wherein a substrate isimpregnated by the composition.
 41. The method of claim 40 wherein thesubstrate comprises at least one member selected from the groupconsisting of fiberglass, quartz, a polyester, a polyamide, a polyimide,a polyamide-imide, a liquid crystalline polymer (LCP), a polyphenylenesulfide (PPS), a polyalkylene, a polyphenylene oxide (PPO), apolybenzoxazoline (PBO), an Aramid, polytetrafluoroethylene, a copolymerof tetrafluoroethylene and perfluoromethylvinyl ether (MFA), and aconductive material.
 42. The method of claim 39 wherein the fillercomprises at least one member selected from the group consisting oftalc, mica, calcium carbonate, calcium sulfate, aluminum nitride, boronnitride, silicon carbide, diamond, graphite, beryllium oxide, magnesia,silica, alumina, Ti0₂, aluminum silicate, zirconium silicate,aluminum-zirconium-silicate, cordierite, silane treated mineral,polytetrafluoroethylene, or polyphenylene sulfide.
 43. The method ofclaim 39 wherein the cured low loss dielectric layer has a dielectricconstant ≦4.5 when measured at 10 GHz.
 44. The method of claim 39wherein the cured low loss dielectric layer has a dielectric loss factor≦0.02 when measured at 10 GHz.
 45. The method of claim 43 wherein thecured low loss dielectric layer has a dielectric loss factor ≦0.02 whenmeasured at 10 GHz.
 46. The method of claim 39 wherein the compositionis applied onto a substrate.
 47. The method of claim 46 wherein thesubstrate comprises at least one member selected from the groupconsisting of fiberglass, quartz, a polyester, a polyamide, a polyimide,a polyamide-imide, a liquid crystalline polymer (LCP), a polyphenylenesulfide (PPS), a polyalkylene, a polyphenylene oxide (PPO), apolybenzoxazoline (PBO), an Aramid, polytetrafluoroethylene, a copolymerof tetrafluoroethylene and perfluoromethylvinyl ether (MFA), and aconductive material.
 48. The method of claim 46 wherein the fillercomprises at least one member selected from the group consisting oftalc, mica, calcium carbonate, calcium sulfate, aluminum nitride, boronnitride, silicon carbide, diamond, graphite, beryllium oxide, magnesia,silica, alumina, Ti0₂, aluminum silicate, zirconium silicate,aluminum-zirconium-silicate, cordierite, silane treated mineral,polytetrafluoroethylene, or polyphenylene sulfide.
 49. The method ofclaim 46 wherein the cured low loss dielectric layer has a dielectricconstant ≦4.5 when measured at 10 GHz.
 50. The method of claim 46wherein the cured low loss dielectric layer has a dielectric loss factor≦0.02 when measured at 10 GHz.
 51. The method of claim 49 wherein thecured low loss dielectric layer has a dielectric loss factor ≦0.02 whenmeasured at 10 GHz.
 52. A pre-preg comprising: a porous substrateimpregnated with a composition comprising: a first resin that forms atriazine structure upon curing, a second resin comprising at least onemember selected from the group consisting of a polyphenylene oxide, astyrene-maleic anhydride copolymer, a carboxy-terminated butadienenitrile resin, a multifunctional epoxy resin, a low-halogen epoxy resinand a bis-maleimide resin, a substantially halogen-free,phosphorus-containing flame retardant having an atomic phosphoruscontent in the range of about 1-20 weight percent, based on the totalweight of the resin components, and a quantity of a particulate filler.53. The pre-preg of claim 52 wherein said substrate is woven ornon-woven.
 54. A laminated sheet produced by layering and molding aprescribed number of sheets of the pre-preg of claim
 52. 55. Thelaminated sheet of claim 54 further comprising one or more conductivelayers.
 56. The laminated sheet of claim 55 wherein said one or moreconductive layers are selected from the group consisting of a metalfoil, a metal plate, and an electrically conductive polymeric layer. 57.A printed wiring board layer produced by forming conductive patterns onthe surface of the laminated sheet of claim
 54. 58. A multilayer printedwiring board produced by layering and molding a prescribed number ofsheets of the patterned laminate layers of claim 58, bonded togetherwith one or more layers of pre-preg from which the printed wiring boardlayer was prepared.
 59. A resin coated electrical component comprising:a substrate, a coating formed on the substrate, the coating being formedfrom a composition comprising: a first resin that forms a triazinestructure upon curing, a second resin comprising at least one memberselected from the group consisting of a polyphenylene oxide, astyrene-maleic anhydride copolymer, a carboxy-terminated butadienenitrile resin, a multifunctional epoxy resin, a low-halogen epoxy resinand a bis-maleimide resin, a substantially halogen-free,phosphorus-containing flame retardant having an atomic phosphoruscontent in the range of about 1-20 weight percent, based on the totalweight of the resin components, and a quantity of a particulate filler.60. The electrical component of claim 59 wherein said substratecomprises a metal foil.
 61. A laminated sheet produced by layering andmolding a prescribed number of sheets of the electrical component ofclaim
 59. 62. The laminated sheet of claim 61 further comprising one ormore conductive layers.
 63. The laminated sheet of claim 62 wherein saidone or more conductive layers are selected from the group consisting ofa metal foil, a metal plate, and an electrically conductive polymericlayer.
 64. A printed wiring board layer produced by forming conductivepatterns on the surface of the laminated sheet of claim
 61. 65. Amultilayer printed wiring board produced by layering and molding aprescribed number of sheets of patterned laminated sheets of claim 64,bonded together with one or more layers of pre-preg from which theprinted wiring board layer was prepared.